Sapstain development on Jack pine logs in Eastern Canada
Dian-Qing Yang, R Beauregard
During 1998-99, a study was initiated to investigate the influence of seasons, log types and storage time on the sapstain development on jack pine logs at two sites in Eastern Canada. Jack pine trees (Pinus banksiana) were harvested into whole-tree and cut-to-length logs in spring and in autumn. Sapstain development was examined in these logs at 2 to 4 week intervals after felling. The mean stain coverage and maximal radial penetration of stain in wood were measured from the discs of the sampled logs. The spring trial showed that sapstain did not develop significantly on jack pine logs within four weeks after trees were cut; however, the severity of stain increased proportionally with the storage time. For both test sites, the full-tree stems were stained more than the cut-to-length logs. All logs were seriously stained after the three months summer storage. The main fungus isolated from stained wood was Ceratocystis coerulescens. Bark beetle attack was found in logs within four weeks after the trees were cut. The bark beetle was Ips pini. After three months in the summer storage, decay started to develop among these logs and the main causal species was Schizophyllum commune.
Keywords: SAPSTAIN; JACK PINE; LOG STORAGE; FUNGAL STAIN; BARK DAMAGE